US4144465A - Self-resetting Josephson device circuit - Google Patents

Self-resetting Josephson device circuit Download PDF

Info

Publication number
US4144465A
US4144465A US05/811,800 US81180077A US4144465A US 4144465 A US4144465 A US 4144465A US 81180077 A US81180077 A US 81180077A US 4144465 A US4144465 A US 4144465A
Authority
US
United States
Prior art keywords
current
josephson
circuit
josephson device
control conductor
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US05/811,800
Other languages
English (en)
Inventor
Sadeg M. Faris
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
International Business Machines Corp
Original Assignee
International Business Machines Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by International Business Machines Corp filed Critical International Business Machines Corp
Priority to US05/811,800 priority Critical patent/US4144465A/en
Priority to JP1061078A priority patent/JPS5412695A/ja
Priority to FR7805796A priority patent/FR2396458A1/fr
Priority to IT20836/78A priority patent/IT1111166B/it
Priority to CA298,268A priority patent/CA1100194A/en
Priority to DE2811188A priority patent/DE2811188C3/de
Priority to GB11001/78A priority patent/GB1579517A/en
Application granted granted Critical
Publication of US4144465A publication Critical patent/US4144465A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03K—PULSE TECHNIQUE
    • H03K3/00—Circuits for generating electric pulses; Monostable, bistable or multistable circuits
    • H03K3/02—Generators characterised by the type of circuit or by the means used for producing pulses
    • H03K3/38—Generators characterised by the type of circuit or by the means used for producing pulses by the use, as active elements, of superconductive devices
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03K—PULSE TECHNIQUE
    • H03K17/00—Electronic switching or gating, i.e. not by contact-making and –breaking
    • H03K17/51—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used
    • H03K17/92—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used by the use, as active elements, of superconductive devices
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S505/00—Superconductor technology: apparatus, material, process
    • Y10S505/825—Apparatus per se, device per se, or process of making or operating same
    • Y10S505/856—Electrical transmission or interconnection system
    • Y10S505/857—Nonlinear solid-state device system or circuit
    • Y10S505/863—Stable state circuit for signal shaping, converting, or generating
    • Y10S505/864—Stable state circuit for signal shaping, converting, or generating with josephson junction

Definitions

  • the present invention relates to circuits including Josephson devices, and more particularly, to a self-resetting Josephson circuit powered by direct current.
  • the present invention makes use of devices capable of supporting Josephson tunnelling currents.
  • the basic theoretical explanation of the Josephson effect is given in an article "Possible New Effects for Conductive Tunnelling" by B. B. Josephson, published in Physics Letters, July 1962, pages 251-53. Since then, numerous other publications have disclosed Josephson devices and proposed their application for a variety of functions.
  • a particular advantage of circuits including Josephson devices is their rapid switching speed and their corresponding capabilities to produce pulses having widths in the pico-second range.
  • a Josephson device is essentially a bi-stable device, in that, in its superconducting or zero voltage state, the device will pass current up to some threshold and so long as the threshold is not exceeded, the device will remain in its zero voltage or superconducting state.
  • the threshold is a function of device parameters as well as any magnetic field in which the device exists.
  • Josephson devices are, in some cases, associated with one or more control conductors which, when a current is applied thereto, produce a magnetic field for reducing the maximum threshold current of the Josephson device.
  • One prior art device a so-called SQUID, an acronym for superconducting quantum interference device, is simply a Josephson device having two or more control conductors which are arranged so that the switching device may be subjected to a magnetic field which is the net result of the magnetic field produced by the control conductors.
  • SQUID an acronym for superconducting quantum interference device
  • the device When the device switches from its zero voltage or superconducting state to the voltage state, by reason of passing a current through the device which exceeds the threshold, the device will remain in the voltage state until such time as the current through the device is reduced to zero, at which time the device will switch back to the zero voltage state. Significantly, merely reducing the current through the device below the threshold will not switch the device back to a zero voltage state.
  • the art in employing Josephson devices, has found it necessary to provide some apparatus or method of operation to reset the Josephson device after it has assumed the voltage state, if it is desired that the device again regains the zero voltage state. Such action is necessary, if, for instance, cyclical operation is desired.
  • the device is reset by applying to it an alternating current, that is, a current having two different polarities. If the device normally conducts current of one sense, the device can be reset when the current applied to it is in the opposite sense. See, for example, "Clock and Power Distribution System for Josephson Tunnelling Logic Networks" by W. Anacker, appearing in the IBM TDB, Volume 16, Number 10, March 1974, pages 3398-99.
  • the device is arranged in a circuit so that no special resetting pulse signal is required for the reason that the necessity for such signals merely delays useful outputs from the Josephson device, and in effect detracts from the reason why the device is being used, i.e., its speed.
  • a self-resetting circuit including a plurality of Josephson devices, which can respond to a selected transition of a square wave input by providing relatively short pulse output, and which, although it resets itself in response to the complementary square wave transition, does not produce a discernible output responsive thereto.
  • the output is produced on the high going transition of the square wave input, while in another embodiment of the invention, the output is produced in the low going transition of the square wave input.
  • the circuit includes a first Josephson device coupled to a dc source of predetermined level; a control conductor associated with the first device is connected to the circuit input.
  • the first Josephson device is arranged to switch to the voltage state in response to the high going transition of the square wave input.
  • a current sinking circuit is connected in parallel with the first Josephson device, the sinking circuit includes a second Josephson device and an inductor.
  • the second Josephson device includes one control conductor coupled to the control conductor of the first Josephson device and which, therefore, carries the same square wave circuit input as does the first Josephson device control conductor.
  • the second Josephson device further includes a second control conductor which is arranged to carry dc of polarity opposite to the circuit input and of amplitude substantially equal to the square wave amplitude such that, in the presence of the circuit input the second Josephson device is subjected to a net zero magnetic field by reason of its control conductors. Accordingly, when the first Josephson device switches to the voltage stage, current begins flowing through the sinking circuit and increases at a constant rate.
  • an output circuit which includes a third Josephson device, a second inductor (which is much smaller than the inductor in the sinking circuit) and a resistance, all connected in series, one terminal of the output circuit is coupled to the dc source driving the circuit.
  • the other terminal of the series output circuit in which an output pulse is produced in response to the high going transition of the circuit input, is connected so that the output circuit, first Josephson device and sinking circuit are all connected in parallel.
  • the output circuit also has one terminal connected to the dc source, but the other terminal of the output circuit is connected between the second Josephson device and the inductor in the current sinking circuit.
  • the first Josephson device when the first Josephson device switches to the voltage state, current flows in both the current sinking circuit and the output circuit, however, by reason of the ratio of the inductors in the output circuit and the current sinking circuit, the current increases in the output circuit at a higher rate.
  • the third Josephson device is arranged, however, with a maximum current level which is less than the current that can be driven through it by the dc source. Accordingly, as the current rises steeply in the output circuit, the maximum current level of third Josephson device is exceeded, and it switches to the voltage state. At this point in time, the current in the output circuit decreases rapidly. Thus, the current in the output circuit is a short pulse substantially occurring at the positive going transition of the circuit input.
  • the current in the current sinking circuit continues to increase in a linear fashion until such time as the current through the first Josephson device is reduced to zero. At this point, the first Josephson device switches to the zero voltage state, and at this point, the current in the current sinking circuit ceases to increase, but remains at a constant level. At about the same time, the third Josephson device also switches to the zero voltage state.
  • the second Josephson device At the negative going transition of the circuit input the second Josephson device is in a condition wherein the current through it exceeds the threshold which has now been reduced because of the net magnetic field to which the device is subjected. Accordingly, the second Josephson device now switches to the voltage state and the current through it begins to decrease to zero; the current is transferred to the first device. When the current through the second device is reduced to zero it also switches to the zero voltage state. At this point in time, the circuit is now reset and on the next positive going transition of the circuit input, the described operation is repeated.
  • the second embodiment operates in a very similar fashion. Assume that the dc current is flowing entirely through the first Josephson device which is in the zero voltage state as are the other two Josephson devices. On the positive transition of the circuit input, the first Josephson device switches to the voltage state and current is thus allowed to flow in the current sinking circuit. Current does not flow in the output circuit because it is coupled across the second Josephson device which is in the zero voltage state; current flow is also opposed by resistor R. Some time after the current is transferred to the current sinking circuit, the first Josephson device switches back to the zero voltage state. At the low going transition of the circuit input, the current flowing through the second Josephson device exceeds the current threshold, which is reduced when the circuit input low going transition occurs, and therefore, the second Josephson device switches to the voltage state.
  • the current flowing through the inductor cannot change instantaneously and thus, current begins flowing in the output circuit.
  • the third Josephson device switches to the voltage state and thus the current through the output circuit drops rapidly.
  • the resulting output is a sharp pulse occurring at the low going transition of the circuit input.
  • the first Josephson device is now in the zero voltage state, current flows therethrough and the second and third Josephson devices are reset to their zero voltage state.
  • the first Josephson device is again switched to the voltage state, and the operation is repeated.
  • FIG. 1 is a schematic circuit diagram of one preferred embodiment
  • FIGS. 2A-2H are waveforms produced in simulating the circuit of FIG. 1;
  • FIG. 3 is a schematic circuit diagram of another embodiment of the invention.
  • FIG. 1 is a circuit diagram of one preferred embodiment of the invention. As illustrated, the circuit includes three Josephson junction devices, Q1, Q2 and Q3. Direct current I g flows to a junction point 10 which is connected to each of the Josephson devices Q1-Q3. The other terminal of Josephson device Q1 is connected to a current sink.
  • a current sinking circuit is connected across Q1 and includes Q2 as well as an inductor L L .
  • An output circuit is also connected across Q1 and includes Q3 as well as an inductor L R and a resistance R. The circuit output is taken across the inductance L R and R.
  • a circuit input is connected to one terminal of a control conductor CONTROL 1 for Q1. Serially connected to this control conductor is a control conductor CONTROL 21 for Q2.
  • the direct current I g flows into the terminal 10 from another control conductor CONTROL 22 for Q2.
  • Q2 is a form of Josephson device known to the art having the form of a split field interferometer or SQUID (acronym for Superconductive Quantum Interference Device). Such a device is disclosed, for example, in U.S. Pat. No. 3,978,351.
  • the net magnetic field to which the Josephson device Q2 is subjected is the result of magnetic fields produced by the currents flowing in both the control conductors 21 and 22.
  • Q1 and Q3 could likewise be SQUIDs.
  • the resistance R can represent the characteristic impedance of a terminated line, and L R is much smaller (at least one order of magnitude) than L L .
  • the current I g should be less than the threshold current I mo of Q1 and Q2, but greater than the threshold current of Q3.
  • I 1 I g , i.e., all the current is flowing through Q1.
  • the circuit input exhibits a positive transition and the amplitude of the positive transition is such that I 1 is greater than the threshold current of Q1 with current flowing in its control conductor by reason of the circuit input waveform.
  • Q1 switches to the voltage state and substantially all the current is switched to the sinking and output circuits.
  • L L > > L R most of the current initially flows through the output circuit.
  • I g is greater than the threshold current of Q3, it too switches to the voltage state when the current I 3 exceeds I mo . Accordingly, I 3 rapidly is reduced. I g flows into the current sinking circuit. The current in the current sinking circuit increases at a constant rate because of the presence of L L . Because the net magnetic field to which Q2 is subjected is essentially zero, since I g is about the same as the current flowing in the control conductor, but of opposite polarity, all the current switches to the current sinking circuit, and both Q1 and Q3 switch back to the zero voltage state. With Q1 in the zero voltage state current in the sinking circuit is stabilized.
  • Suitable values for the circuit of FIG. 1 to produce an output pulse on the order of 50 pico-seconds include the following parameters:
  • I g 1.5 mA and the circuit input has a 950 pico-second period with a transition from 0 mA to 1.5 mA.
  • control current 22 for Q2 need not actually comprise I g , but can be supplied from another source, which source may have its current amplitude selected in accordance with the desired functioning of Q2 in the circuit.
  • Q3 has been disclosed as a single junction, it may also be a split field interferometer and the control currents to which the device is subjected may be selected in accordance with the desired operation.
  • the circuit input employed a waveform such as that shown in FIG. 2A.
  • the current through Q1 is shown in FIG. 2B
  • the current through Q3 is shown in FIG. 2C
  • the current in Q2 is shown in FIG. 2D
  • FIG. 2E illustrates the magnetic field to which Q2 is subjected, being the difference between I g and the circuit input waveform (FIG. 2A).
  • the voltage across Q1, Q2 and Q3 is shown respectively in FIGS. 2F, 2G and 2H.
  • the waveform of FIG. 2C, that is, the current through Q3, is also an indication of the output voltage available across L R and the resistance.
  • the circuit of FIG. 1 provides a short output pulse on each positive transition of an input square waveform. It is sometimes desirable to be able to produce a short output pulse on the negative going transition of a square wave input waveform.
  • the circuit of FIG. 1 can be employed to perform such a function with a slight modification as shown, for example, in FIG. 3.
  • the Josephson device Q1 has applied to it a direct gate current I g .
  • a sinking circuit is connected across Q1 which sinking circuit is, as in FIG. 1, comprised of a second Josephson device Q2 and an inductor L L .
  • the same output circuit comprising Josephson device Q3, inductor L R and a resistance R has one terminal connected to the circuit point 10, as in FIG. 1.
  • the output circuit is now connected across the Josephson device Q2, rather than being connected across the Josephson device Q1.
  • the same parameters discussed above with regard to FIG. 1 can be employed in the circuit of FIG. 3. In operation, we can assume that the gate current is flowing entirely through Q1 when the circuit input is zero.
  • FIGS. 1 and 3 are complementary in that the circuit of FIG. 1 produces an output pulse on one transition of an input square waveform, whereas the circuit of FIG. 3 produces an output pulse on the other transition.
  • Both circuits can be viewed as including a first current conducting circuit with a Josephson device normally carrying current and responsive to a first transition in the circuit input for switching to a voltage state to thereby impede current flow therethrough, an output circuit connected in parallel with the Josephson device and including a second Josephson device therein for producing an output pulse with a leading edge formed as current switches into the output circuit and a trailing edge as the current through the second Josephson device exceeds its threshold and it switches to a voltage state to thereby steer current out of said output circuit, and a resetting circuit means which responds to the complementary transition in the input waveform to switch current back to the first current conducting circuit.
  • the first Josephson device is Q1
  • the output circuit includes Q3
  • the resetting circuit includes Q2.
  • the first current conducting circuit is Q1
  • the output circuit includes Q
  • the circuit operation can be made selective by arranging Q3 to have a threshold I Mo exceeding I g and associating a control conductor therewith. Accordingly, in the absence of control current in the conductor, the output produces broad, rather than short pulses. In the presence of current in the third Josephson device's control conductor, reducing I Mo below Ig, the short pulses will be produced. The amplitude and duration of such pulses can be altered by means of the control current associated with Q3.

Landscapes

  • Superconductor Devices And Manufacturing Methods Thereof (AREA)
  • Electronic Switches (AREA)
  • Manipulation Of Pulses (AREA)
  • Logic Circuits (AREA)
US05/811,800 1977-06-30 1977-06-30 Self-resetting Josephson device circuit Expired - Lifetime US4144465A (en)

Priority Applications (7)

Application Number Priority Date Filing Date Title
US05/811,800 US4144465A (en) 1977-06-30 1977-06-30 Self-resetting Josephson device circuit
JP1061078A JPS5412695A (en) 1977-06-30 1978-02-03 Selffreset josephson circuit
FR7805796A FR2396458A1 (fr) 1977-06-30 1978-02-23 Circuit a reenclenchement automatique a dispositifs de josephson
IT20836/78A IT1111166B (it) 1977-06-30 1978-03-03 Circuito josephon a riprostino automatico
CA298,268A CA1100194A (en) 1977-06-30 1978-03-06 Self-resetting josephson device circuit
DE2811188A DE2811188C3 (de) 1977-06-30 1978-03-15 Josephson-Schaltkreis mit automatischer Rückstellung
GB11001/78A GB1579517A (en) 1977-06-30 1978-03-20 Josephson device circuits

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US05/811,800 US4144465A (en) 1977-06-30 1977-06-30 Self-resetting Josephson device circuit

Publications (1)

Publication Number Publication Date
US4144465A true US4144465A (en) 1979-03-13

Family

ID=25207620

Family Applications (1)

Application Number Title Priority Date Filing Date
US05/811,800 Expired - Lifetime US4144465A (en) 1977-06-30 1977-06-30 Self-resetting Josephson device circuit

Country Status (7)

Country Link
US (1) US4144465A (it)
JP (1) JPS5412695A (it)
CA (1) CA1100194A (it)
DE (1) DE2811188C3 (it)
FR (1) FR2396458A1 (it)
GB (1) GB1579517A (it)
IT (1) IT1111166B (it)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4489424A (en) * 1981-05-14 1984-12-18 Nippon Electric Co., Ltd. Frequency divider making use of Josephson junction circuits
US4948999A (en) * 1981-05-21 1990-08-14 U.S. Philips Corporation Self-starting two-pole single-phase synchronous motor
CN110311662A (zh) * 2019-05-27 2019-10-08 中国科学院计算技术研究所 超导环及超导高频时钟发生器
US11346872B1 (en) 2018-12-19 2022-05-31 Synopsys, Inc. Direct measurement of Josephson junction capacitance

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4210921A (en) * 1978-06-30 1980-07-01 International Business Machines Corporation Polarity switch incorporating Josephson devices
US4274015A (en) * 1978-12-29 1981-06-16 International Business Machines Corporation Self-resetting Josephson digital current amplifier
JPS6113826U (ja) * 1984-06-29 1986-01-27 俊夫 松枝 眼鏡チエンホルダ−における眼鏡つる保持具
US10236869B2 (en) * 2016-11-18 2019-03-19 Northrop Grumman Systems Corporation Superconducting transmission driver system

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
D. J. Herrell, "Josephson Multivibrator and Monostable Circuits," IBM Technical Disclosure Bulletin, vol. 17, No. 10, Mar. 1975, pp. 3082-3083. *

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4489424A (en) * 1981-05-14 1984-12-18 Nippon Electric Co., Ltd. Frequency divider making use of Josephson junction circuits
US4948999A (en) * 1981-05-21 1990-08-14 U.S. Philips Corporation Self-starting two-pole single-phase synchronous motor
US11346872B1 (en) 2018-12-19 2022-05-31 Synopsys, Inc. Direct measurement of Josephson junction capacitance
CN110311662A (zh) * 2019-05-27 2019-10-08 中国科学院计算技术研究所 超导环及超导高频时钟发生器

Also Published As

Publication number Publication date
DE2811188A1 (de) 1979-05-17
IT7820836A0 (it) 1978-03-03
DE2811188B2 (de) 1979-09-13
FR2396458A1 (fr) 1979-01-26
GB1579517A (en) 1980-11-19
JPS5412695A (en) 1979-01-30
JPS5711511B2 (it) 1982-03-04
FR2396458B1 (it) 1980-08-29
DE2811188C3 (de) 1980-05-29
IT1111166B (it) 1986-01-13
CA1100194A (en) 1981-04-28

Similar Documents

Publication Publication Date Title
US4117354A (en) Two-part current injection interferometer amplifiers and logic circuits
EP0045349B1 (en) Superconductive latch circuit
GB809205A (en) Magnetically controlled gating element
Gheewala Josephson-logic devices and circuits
US4144465A (en) Self-resetting Josephson device circuit
CA1163727A (en) Superconducting soliton devices
US4274015A (en) Self-resetting Josephson digital current amplifier
US4611132A (en) Circuit utilizing Josephson effect
US2783456A (en) Phase responsive bistable devices
US4559459A (en) High gain non-linear threshold input Josephson junction logic circuit
US2909674A (en) High frequency relay
Baechtold A flip-flop and logic gate with Josephson junctions
US4489424A (en) Frequency divider making use of Josephson junction circuits
CA1047127A (en) Superconductive sensing circuit for providing improved signal-to-noise
EP0066239A2 (en) Pulse generation circuit using at least one Josephson junction device
Fulton et al. A Josephson logic design employing current-switched junctions
US4373138A (en) Hybrid unlatching flip-flop logic element
US3070708A (en) Logical circuits
US2981933A (en) Multistable circuit
Chan et al. High-speed switching and logic circuits using Josephson devices
GB1498860A (en) Superconductive sensing circuits
US3156833A (en) Sense circuits employing tunnel diodes or the like
US3201614A (en) Logic circuit
EP0087764A1 (en) Josephson pulse generator of current injection type
US3230393A (en) Sequential switching circuit which employs the turn-off delay of a saturated transistor for interim storage